如何在底部导航片段（或导航抽屉）之间传递数据？

Question

I have a situation, I´m not good enough in android dev to implement a way to pass data between Bottom Navigation destinations.

I would need to get text from EditText from CreateFragment to a RecipesFragment, where I would add a new item in the database and the RecyclerView would update (I´m using LiveData + MVVM) based on this data.

My Bottom Navigation Bar

So, I´m asking for a way. I couldn´t find any proper/specific explanation and I think that passing data between fragments in Bottom Navigation or Navigation Drawer is important feauture but hard i guess for beginners like me:(.

Additional info: I host a FrameLayout(id-fragment_container) in my MainActivity in what I change fragments based on location in Bottom Nav selected. (check code)

MainActivity.java

public class MainActivity extends AppCompatActivity {
private BottomNavigationView bottomNavigationView;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    bottomNavigationView = findViewById(R.id.bottom_navigation);
    bottomNavigationView.setOnNavigationItemSelectedListener(navListener);

    // Keeps the current fragment opened when the device rotates
    if (savedInstanceState == null) {

        // Sets the default selected item in NavigationView
        bottomNavigationView.setSelectedItemId(R.id.nav_home);
    }
}

// Handles switching the view based on NavigationView item selected
private BottomNavigationView.OnNavigationItemSelectedListener navListener =
        new BottomNavigationView.OnNavigationItemSelectedListener() {
            @Override
            public boolean onNavigationItemSelected(@NonNull MenuItem item) {
                Fragment selectedFragment = null;

                switch (item.getItemId()) {
                    case R.id.nav_home:
                        selectedFragment = new HomeFragment();
                        break;
                    case R.id.nav_recipes:
                        selectedFragment = new RecipesFragment();
                        break;
                    case R.id.nav_create:
                        selectedFragment = new CreateFragment();
                        break;
                }

                getSupportFragmentManager().beginTransaction().replace(R.id.fragment_container,
                        selectedFragment).commit();

                return true;
            }
        };

CreateFragment.java

private void saveRecipe() { //trigered on floating button press
    String title = edit_title.getText().toString();
    String ingredients = edit_ingredients.getText().toString();

    if (title.trim().isEmpty() || ingredients.trim().isEmpty()) {
        Toast.makeText(getActivity(), "Please insert a title and description", Toast.LENGTH_SHORT).show();
        return;
    }

    // THIS SHOULD PASS DATA TO RecipesFragment INTO RECYCLERVIEW
    // TODO

    //
}

RecipesFragment.java

    public void getRecipeFromCreateFragment() {

    // THERE SHOULD BE PASSED DATA FROM CREATE ACTIVITY
    // TODO





    //

    Recipe recipe =
            new Recipe("hh", "title", "ingredients", "instructions", "ss", "image");
    recipeViewModel.insert(recipe);

    Toast.makeText(getActivity(), "Recipe saved", Toast.LENGTH_SHORT).show();
}

Answer 1

UPDATE: Okay, I got help from a fellow redditer and the solution was really easy and I shouldn´t had even thought about passing data between fragments in my case.

The solution is to simply add the recipe to the database via ViewModel in the CreateFragment, there´s really no need to pass the data to the RecipesFragment and then add it there.

HOWEVER, if someone know a better, more recommended way to pass data between fragments in Navigation View (Navigation Drawer) it would be really helpful for the future.

Thanks.